Image forming apparatus

Abstract

This invention discloses an image forming apparatus, comprising an image carrier member, a rotatable developer carrier member, a first drive unit for rotating the developer carrier member, a developer storage unit for accommodating the developer carrier member and storing developer, a rotatable stirring member configured to stir the developer, a second drive unit for rotatably driving the stirring member, a developer detection unit for detecting information about the developer in the developer storage unit, an attachment portion for detachably receiving a replenishment container and including a replenishment port communicating with the developer storage unit, and a control unit. During replenishment operations, while the rotation of the developer carrier member and the stirring member is stopped, developer is replenished from the replenishment container into the developer storage unit through the replenishment port, and the control unit controls the first drive unit and the second drive unit based on information about the developer.

Description

Technical Field

[0001] This disclosure relates to an image forming apparatus that uses electrophotographic processing or the like to form an image on a recording medium. Background Technology

[0002] Typically, electrophotographic image forming apparatuses form images on recording materials by transferring a toner image formed on the surface of a photosensitive drum onto the recording material. For example, a known toner replenishment method is a method of supplying new toner when image formation is insufficient due to the consumption of toner used as a developer during the image forming process. The toner replenishment method is a method that resupplyes toner to the developer container when the remaining toner level is low without requiring component replacement. Japanese Patent Application Publication No. 2022-27631 describes a configuration of a toner replenishment method (hereinafter referred to as the direct toner replenishment method) in which a toner packet is attached to a developer container with a portion of the toner packet exposed to the outside, and the toner stored in the toner packet is uniformly replenished into the developer container.

[0003] However, the configuration described in Japanese Patent Publication No. 2022-27631 has the following problem. The configuration described in Japanese Patent Publication No. 2022-27631 can detect the remaining amount of toner being consumed and the remaining amount of toner after replenishment via a toner remaining amount detection unit, and report the detected toner remaining amount to the user. The toner remaining amount detection unit identifies the amount of toner in the developer container while the toner is stirred by a stirring member installed in the developer container. Therefore, the toner replenishment operation in the configuration described in Japanese Patent Publication No. 2022-27631 involves at least the rotational drive of the stirring member.

[0004] Therefore, as described in Japanese Patent Publication No. 2022-27631, when driving the stirring member in a developer container that is not filled with toner, for example when the device is brand new, component damage may occur. In particular, the risk of damage to the rotatable member increases when the stirring member and another rotatable member are driven together. Summary of the Invention

[0005] This disclosure aims to ideally perform the replenishment of toner into the developer container while minimizing damage to components.

[0006] The image forming apparatus according to this application provides means for solving the above-mentioned problems. In general, a representative configuration of this disclosure is as follows: An image forming apparatus includes an image carrier member; a rotatable developer carrier member configured to supply developer to the image carrier member; a first drive unit configured to rotatably drive the developer carrier member; a developer storage unit on which the developer carrier member is disposed and where developer is stored; a rotatable stirring member disposed in the developer storage unit and configured to stir the developer; a second drive unit configured to rotatably drive the stirring member; a developer detection unit disposed in the developer storage unit; an attachment portion including a replenishment port communicating with the developer storage unit and configured to detachably receive a replenishment container; and a component configured to control the first drive unit and... The control unit of the second drive unit is configured to perform a replenishment operation for replenishing developer to the developer storage unit, wherein during the replenishment operation, the developer is replenished from a replenishment container attached to the attachment portion through the replenishment port to the developer storage unit, wherein the replenishment operation is performed with the rotation of the developer carrier and the stirring member stopped, without performing rotation operation of the developer carrier and the stirring member, and wherein the control unit is configured to control the first drive unit and the second drive unit based on information about the developer during the replenishment operation.

[0007] The features of this disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of embodiments is by way of example. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view of the image forming apparatus according to the first embodiment.

[0009] Figure 2 This is a perspective view of the stirring component according to the first embodiment.

[0010] Figure 3 This is a perspective view of the image forming apparatus according to the first embodiment.

[0011] Figure 4A and Figure 4B These are perspective and front views of the processing box and toner packet according to the first embodiment, respectively.

[0012] Figure 5 This is a perspective view of the toner packet according to the first embodiment.

[0013] Figure 6 This is a schematic plan view showing the optical path of the laser in the exposure unit according to the first embodiment.

[0014] Figures 7A to 7CThis is a diagram illustrating a toner remaining quantity detection sensor according to the first embodiment.

[0015] Figure 8 This is a diagram illustrating an example of the circuit configuration of a toner remaining quantity detection sensor according to the first embodiment.

[0016] Figure 9 This is a block diagram illustrating the control system of the image forming apparatus according to the first embodiment.

[0017] Figure 10 This is a diagram showing the voltage waveforms at toner levels FULL and LOW according to the first embodiment.

[0018] Figure 11 This is a diagram showing the voltage waveform when the toner stops filling according to the first embodiment.

[0019] Figures 12A to 12D These are diagrams showing cross-sectional images, transmission images, and voltage waveforms when the phase of the stirring member changes according to the first embodiment.

[0020] Figure 13 This is a flowchart illustrating the operations to be performed before and after the toner filling operation according to the first embodiment.

[0021] Figure 14 This is a diagram showing the voltage waveform, cross-sectional image, and transmission image according to the second embodiment.

[0022] Figure 15 This is a diagram showing the voltage waveform, cross-sectional image, and transmission image according to the third embodiment. Detailed Implementation

[0023] In the following, embodiments for implementing this disclosure will be described in detail illustratively with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described in these embodiments will be appropriately modified according to the configuration of the apparatus to which this disclosure is applied and various conditions. That is, the scope of this disclosure is not limited to the following embodiments.

[0024] 1. Image forming apparatus Figure 1 This is a schematic cross-sectional view illustrating the structure of the image forming apparatus 1 according to the first embodiment of the present disclosure. Figure 3 This is a perspective view of the image forming apparatus 1 according to this embodiment. The image forming apparatus 1 is a monochrome printer that forms an image on a recording material P based on image information input from an external device.

[0025] Figure 1The image forming apparatus 1 is shown mounted on a horizontal plane. This is a commonly assumed mounting state of the image forming apparatus 1, and the directions on the plane are defined as follows: The up-down direction in the figure is the vertical direction (direction of gravity). The upward and downward directions in the figure will be referred to as the "upward direction" and "downward direction," respectively. The leftward direction in the figure will be referred to as the rearward direction (from the front surface side of the apparatus to the rear side), and the rightward direction in the figure will be referred to as the forward direction (from the rear surface side of the apparatus to the front side). Furthermore, the forward direction in the figure (from the rear side of the figure to the front side of the figure, perpendicular to the plane of the figure) will be referred to as the leftward direction, and the rearward direction (from the front side of the figure to the rear side of the figure, perpendicular to the plane of the figure) will be referred to as the rightward direction.

[0026] The image forming unit 10 includes a scanner unit 11, an electrophotographic processing cartridge 20, and a transfer roller 12, which transfers a toner image formed on a photosensitive drum 21, which serves as an image carrier component disposed in the processing cartridge 20, to a recording material P.

[0027] Processing cartridge 20 includes a photosensitive drum 21, a charging roller 22, a pre-exposure device 23, and a developing device 30 including a developing roller 31 (developer carrier) arranged around the photosensitive drum 21. Image forming apparatuses to which the techniques of this disclosure can be applied are not limited to image forming apparatuses having the same basic construction as the image forming apparatus 1 described in the first embodiment. For example, an image forming apparatus may be a color laser printer that includes multiple processing cartridges 20 serving as image forming units and intermediate transfer members such as intermediate transfer belts, and forms color images on recording material P using toners of various colors.

[0028] According to this embodiment, the processing box 20 is configured to be replaceable by a user by attaching to and removing from the image forming apparatus 1. Alternatively, the processing box 20 may be fixed to the image forming apparatus 1 in a configuration that does not assume user attachment and removal. That is, the processing box 20 may be configured as a processing unit that can be considered part of the main body of the device.

[0029] The processing box 20 is configured to be easily attached to or detached from the image forming apparatus 1 by means of attachment guides and positioning members provided on one or both of the image forming apparatus 1 and the processing box 20.

[0030] Furthermore, the image forming apparatus 1 includes a transfer roller 12 serving as a transfer unit and a fixing device 70 serving as a fixing unit (fixer). The transfer roller 12 is a roller-shaped transfer member arranged to contact the surface of the photosensitive drum 21. The fixing device 70 includes, for example, a fixing roller (fixing member) 71 having a built-in halogen lamp serving as a heating unit and a pressure roller (pressure member) 72 in pressure contact with the fixing roller 71. A fixing clamping portion is formed between the fixing roller 71 and the pressure roller 72. The fixing device 70 can be, for example, an induction heater (IH) fixing device using an induction heating coil as a heating unit, or a ceramic heater in which a pattern of heating resistors is printed on a ceramic substrate can be used as a heating unit. Furthermore, the fixing member 71 can be, for example, a cylindrical film. The fixing member 71 and the pressure member 72 can be annular members (fixing belts) extending around a plurality of rollers.

[0031] Furthermore, the image forming apparatus 1 includes a control unit 90 that oversees the control of the entire image forming apparatus 1 and an operation panel 300 that serves as an operation unit. The operation panel 300 includes a display unit 301 for displaying information to an operator, such as a user or service personnel, under the control of the control unit 90, and an input unit 302 for inputting information to the control unit 90 based on operations performed by the operator. The display unit 301 includes a liquid crystal panel. The input unit 302 includes a touch panel structure for the liquid crystal panel and physical buttons, such as a print execution button.

[0032] The photosensitive drum 21, used as an image carrier, is a cylindrical photosensitive component. According to this embodiment, the photosensitive drum 21 includes a photosensitive layer formed of a negatively charged organic photosensitive component on a drum-shaped substrate made of aluminum. Furthermore, the photosensitive drum 21 is composed of… Figure 9 The drive motor M1 shown travels along a predetermined direction at a predetermined processing speed. Figure 1 The rotation drive is clockwise.

[0033] The charging roller 22, serving as a charging component, contacts the photosensitive drum 21 with a predetermined pressure contact force, forming a charging unit. Furthermore, the charging power supply E1, serving as a charging voltage application unit, applies a desired charging voltage, thereby uniformly charging the surface of the photosensitive drum 21 to a predetermined potential. In this embodiment, the photosensitive drum 21 is charged to a negative polarity by the charging roller 22. Therefore, the charging roller 22 uniformly performs the charging process to charge the surface of the photosensitive drum 21 to a predetermined potential with a predetermined polarity (negative polarity in the first embodiment). In the first embodiment, a charging voltage of -1400V is applied to the charging roller 22 to make the surface potential of the photosensitive drum 21 after the charging process, i.e., the pre-exposure potential VD (dark area potential), become -800V. In the first embodiment, a DC voltage is used as the charging voltage, but the charging voltage is not limited to this, and a vibration voltage obtained by superimposing a DC voltage and an AC voltage can be used as the charging voltage. In order to create a stable discharge in the charged unit, the pre-exposure device 23 neutralizes the surface potential of the photosensitive drum 21 before it enters the charged unit.

[0034] like Figure 6 As shown, the scanner unit 11, serving as an exposure unit, uses a multifaceted mirror (deflector) 113 to irradiate the photosensitive drum 21 with a laser corresponding to image information input from an external device, thereby performing scanning exposure on the surface of the photosensitive drum 21. The exposure forms an electrostatic latent image corresponding to the image information on the surface of the photosensitive drum 21. In the first embodiment, the scanner unit 11 includes a laser scanner unit. In the first embodiment, the scanner unit 11 operates at, for example, 0.45 μJ / cm². 2 The laser beam is emitted onto the surface of the photosensitive drum 21, causing the post-exposure potential VL (bright area potential) (i.e., the potential of the surface of the photosensitive drum 21 after it has been irradiated by light from the scanner unit 11) to become -100 V. The scanner unit 11 is not limited to laser scanner devices; for example, it can be a light-emitting diode (LED) exposure device including an LED array in which multiple LEDs are arranged along the long side of the photosensitive drum 21.

[0035] The developing apparatus 30 includes a developer container 32 (frame body) serving as a developer storage unit for storing developer, a developing roller 31 serving as a developer carrier member for carrying developer, and a supply roller 33 serving as a developer supply member that contacts the developing roller 31 and can supply developer to the developing roller 31. Toner, used as developer, stored in the developer container 32, is applied to the surface of the developing roller 31 by the supply roller 33. The developer container 32 includes a developing chamber 32e in which the developing roller 31 and the supply roller 33 are arranged, and a toner storage chamber 32d communicating with the developing chamber 32e and storing the toner to be supplied to the developing chamber 32e. The developer container 32 is provided with a protrusion A (e.g., Figure 1As shown, the toner to be supplied to the developing roller 31 and the supply roller 33 is stored in the developing chamber 32e. The boundary between the developing chamber 32e and the toner storage chamber 32d, located at the position corresponding to the protrusion A, will be referred to as the developing opening 39. The supply roller 33 is not necessarily required as long as the toner can be adequately supplied to the developing roller 31.

[0036] According to this embodiment, the developing method used in the developing apparatus 30 is a contact developing method. That is, the toner layer carried on the developing roller 31 contacts the photosensitive drum 21 at the developing section where the photosensitive drum 21 and the developing roller 31 face each other. Alternatively, the configuration of this embodiment can be applied to non-contact developing, wherein the photosensitive drum 21 and the developing roller 31 do not contact each other at the developing section where the photosensitive drum 21 and the developing roller 31 face each other.

[0037] A developing voltage is applied to the developing roller 31 via a developing power supply E2, which serves as the developing voltage application unit. In the first embodiment, a developing voltage of -400V is applied to the developing roller 31. Then, toner charged to the same polarity as the charged electrode of the photosensitive drum 21 adheres to the area (exposed area, image area) on the photosensitive drum 21. In this area, after uniform charging (reverse development method), the absolute value of the potential decreases due to exposure. The charged toner does not adhere to the areas that are not exposed (unexposed area, non-image area), and the surface potential remains at the pre-exposure potential VD.

[0038] In this embodiment, a toner with an average particle size of approximately 6 micrometers (μm) and negative polarity is used as the normal polarity. As an example of the toner according to this embodiment, a polymerized toner produced by a polymerization method is employed. Furthermore, the toner according to this embodiment is a so-called non-magnetic single-component developer without magnetic components, and is mainly carried by the developing roller 31 by intermolecular forces or electrostatic forces (image forces).

[0039] However, single-component developers containing magnetic components can be used. Furthermore, in addition to toner particles, single-component developers can also contain additives (such as wax or silica particles) to adjust the toner's flowability and electrical properties. Alternatively, two-component developers containing a non-magnetic toner and a magnetic carrier can be used. In the case of using a magnetic developer, for example, a cylindrical developing sleeve in which magnets are arranged serves as the developer carrier.

[0040] The doctor blade 35 adjusts the toner dosage carried by the developing roller 31. As the developing roller 31 rotates, the toner supplied to the surface of the developing roller 31 becomes uniformly thinned as it passes through the portion facing the doctor blade 35, and is charged to a negative polarity through triboelectric charging.

[0041] Furthermore, the stirring member 34 is rotatably disposed within the toner storage chamber 32d of the developer container 32. Additionally, a toner remaining quantity detection sensor (developer remaining quantity detection unit) 50, serving as an optical detection unit, is disposed on the inner wall of the toner storage chamber 32d. The toner remaining quantity detection sensor 50 has an optical path for detection light within the toner storage chamber 32d, and detects the amount of toner stored in the toner storage chamber 32d based on the amount of detection light passing through the optical path. The configuration details of the toner remaining quantity detection sensor 50 will be described below in the section on toner remaining quantity detection method.

[0042] Figure 2 This is a schematic perspective view showing the construction of the stirring member 34. The stirring member 34 includes a stirring shaft (rotatable member) 34a extending along its long side, a blade portion (first blade) 34b extending radially outward from the stirring shaft 34a, and a cleaning member (second blade) 34f extending radially outward from the stirring shaft 34a at a different position than the blade portion 34b. The cleaning member 34f is provided for cleaning the toner remaining amount detection sensor 50. In this embodiment, the cleaning member 34f is located 90° downstream of the blade portion 34b in the rotation direction of the stirring shaft 34a.

[0043] Specifically, the stirring shaft 34a has a first attachment surface 34a1 extending along the direction of rotation and a second attachment surface 34a2 extending along the direction of rotation at a position different from the first attachment surface 34a1 around the rotation axis. The first attachment surface 34a1 and the second attachment surface 34a2 are two adjacent surfaces among four surfaces arranged along the direction of rotation of the stirring shaft 34a having a rectangular cross-section, and are surfaces having perpendicular lines (normals) extending in directions orthogonal to each other.

[0044] The blade portion (first blade) 34b1 includes an attachment portion (first attachment portion) 34b11 that contacts the first attachment surface 34a1. The blade portion 34b1 has one end (first end) 34be1 that is fixed to the stirring shaft 34a in a direction orthogonal to the rotation axis as part of the attachment portion 34b11, and another end (second end) 34be2 that is a free end and can contact the inner wall surface of the toner storage chamber 32d.

[0045] The cleaning member (second piece) 34f includes an attachment portion (second attachment portion) 34f1 that contacts the second attachment surface 34a2. The cleaning member 34f has one end (third end) 34fe1 in a direction orthogonal to the rotation axis, which is fixed to the stirring shaft 34a as part of the attachment portion 34f1, and another end (fourth end) 34fe2 that can contact the toner remaining quantity detection sensor 50. More specifically, the cleaning member 34f is configured to clean the toner remaining quantity detection sensor 50 by contacting the optical path surface of the toner remaining quantity detection sensor 50, which forms an optical path for detecting light in the toner storage chamber 32d.

[0046] When viewed from the rotation axis direction of the stirring shaft 34a, the length of the blade portion 34b, measured along the direction extending from the attachment portion 34b1 to its end, is longer than the length of the cleaning member 34f, measured along the direction extending from the attachment portion 34f1 to one end. Furthermore, in the long side direction corresponding to the rotation axis direction of the stirring shaft 34a, the width of the cleaning member 34f is narrower than the width of the blade portion 34b. That is, the width of the cleaning member 34f corresponds to the long side width of the toner remaining amount detection sensor 50, while the width of the blade portion 34b corresponds to the long side width of the toner storage chamber 32d. Moreover, since the long side width of the blade portion 34b is narrower than the long side width of the developing opening 39, the short side length of the blade portion 34b (the length of the blade portion 34b measured along the direction extending when viewed from the rotation axis direction) is the length that allows the blade portion 34b to enter the developing chamber 32e via the developing opening 39.

[0047] The stirring member 34 rotates around the stirring shaft 34a as the center of rotation by driving the drive motor M1, which serves as the first drive unit, via the gear 34c.

[0048] The blade portion 34b of the stirring member 34 according to this embodiment is made of polycarbonate with a thickness of 180 μm, such that the blade portion is configured to be substantially flexible. The blade portion 34b stirs the toner in the developer container 32 while bending according to the inner wall shape of the developer container 32 and returning to its original shape. The long side width W of the blade portion 34b of the stirring member 34 is set to be narrower than the long side width of the developing opening 39, and the blade portion 34b can enter the developing opening 39. The blade portion 34b also has the function of conveying toner towards the developing chamber 32e, in which the developing roller 31 and the supply roller 33 are arranged, via the developing opening 39.

[0049] Furthermore, the cleaning component 34f in this embodiment has the function of preventing toner that has fallen onto the toner remaining amount detection sensor 50 from contaminating the optical path, thereby reducing the possibility of situations where the detection accuracy of the toner remaining amount cannot be guaranteed. As the cleaning component 34f in this embodiment, a cleaning component made of a polyimide sheet with high abrasion resistance and a thickness of 200 μm is used, so that it can fully withstand repeated friction on the optical path surface of the toner remaining amount detection sensor 50.

[0050] 2. Image Formation Operations Reference Figure 1 The image forming operation of the image forming apparatus 1 is described.

[0051] If a command is input to the control unit 90 of the image forming apparatus 1, a print job begins. Based on image information input from an external computer or the like connected to the image forming apparatus 1, the image forming unit 10 performs image forming processing P2. Before and after image forming processing P2, rotational preprocessing P1 as a preparation process for image forming and rotational postprocessing P3 as a postprocessing process are typically provided.

[0052] In the rotational preprocessing P1, the drive motor M1, the scanner unit 11, the various high-voltage power supplies E1, E2 and E3, and the fixing unit 70 are started and stabilized. When each unit has been started, that is, when each unit becomes capable of performing image forming, or when it is expected to be capable of performing image forming, the rotational preprocessing P1 ends and the image forming process P2 begins.

[0053] In image forming process P2, based on the input image information, scanner unit 11 emits laser L to photosensitive drum 21 (see [link]). Figure 1 At this point, the photosensitive drum 21 is pre-charged by the charged roller 22, and an electrostatic latent image is formed on the photosensitive drum 21 by irradiation with laser L. Subsequently, the electrostatic latent image is developed by the developing roller 31, and a toner image is formed on the photosensitive drum 21.

[0054] Simultaneously with image formation processing P2, the feed unit 60 conveys the recording material P toward the transfer clamping section formed by the transfer roller 12 and the photosensitive drum 21. A transfer voltage is applied to the transfer roller 12 by a transfer power supply E3, which serves as a transfer voltage application unit, and the toner image carried on the photosensitive drum 21 is transferred onto the recording material P. In the first embodiment, a transfer voltage of +1500V is applied to the transfer roller 12.

[0055] The recording material P, on which the toner image is transferred, is conveyed to the fixing unit 70, and the toner image is heated and pressurized as the recording material P passes through the clamping part between the fixing roller 71 and the pressure roller 72 of the fixing unit 70.

[0056] Therefore, the toner particles melt and then solidify, thereby fixing the toner image onto the recording material P.

[0057] On the other hand, during the transfer process, toner that was not transferred to the recording material P at the transfer section TS and remains on the photosensitive drum 21 (transfer residual toner) is removed from the surface of the photosensitive drum 21 as follows. Meanwhile, the recording material P on which the toner image has been formed and which has passed through the fixing unit 70 is discharged to the outside of the image forming apparatus 1 via the discharge roller pair 80, which serves as the discharge unit, and stacked on the discharge tray 81, which serves as the stacking portion, formed in the upper part of the image forming apparatus 1. After all the recording material P sent to the discharge tray 81 has been discharged, or after the image forming process P2 is completed, the image forming apparatus 1 switches to the rotational post-processing P3.

[0058] In the rotation post-processing P3, various high-voltage power supplies are shut off, and the fixing unit 70 is rotated at a temperature lower than that used during the sheet passage temperature control or when the temperature control is off, in order to equalize the temperature difference between the sheet passage portion and the non-sheet passage portion.

[0059] 3. Toner collection without a cleaner As described below, the toner (transfer residue toner) that was not transferred to the recording material P during the transfer process and remained on the photosensitive drum 21 is removed from the surface of the photosensitive drum 21.

[0060] The pre-exposure device 23 releases static electricity from the surface of the photosensitive drum 21 in such a way that, after the photosensitive drum 21 passes through the transfer section, the surface potential becomes approximately 0V, and then the photosensitive drum 21 enters the charging unit. The pre-exposure device 23 performs static electricity elimination, for example, by emitting light across the entire surface area of ​​the photosensitive drum 21. Even after the photosensitive drum 21 passes through the transfer section, the toner remaining on the photosensitive drum 21 (hereinafter referred to as transfer residual toner) includes both positively and negatively polarized toner, but the toner is mixed and does not possess sufficient charge. Through the static electricity release of the charging roller 22, the transfer residual toner is charged to a negative polarity in the charging unit.

[0061] As the photosensitive drum 21 rotates, the negatively charged transfer residue toner in the charged unit reaches the developing section. Here, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 21 that has reached the developing section. The transfer residue toner adhering to the unexposed area (non-image area) of the photosensitive drum 21 moves from the photosensitive drum 21 to the developing roller 31 in the developing section due to the potential difference between the pre-exposure potential VD of the photosensitive drum 21 and the developing voltage, and is collected in the developing apparatus 30.

[0062] The toner collected in the developing apparatus 30 is mixed with the toner in the developing apparatus 30 and reused for image formation.

[0063] In this manner, the image forming apparatus 1 according to this embodiment employs a configuration (simultaneous development and cleaning method) in which residual toner on the photosensitive drum 21 is collected into the developer container 32 by the developing roller 31. This residual toner has not yet been transferred to the recording material P used as the transfer material in the transfer section. Furthermore, the image forming apparatus 1 according to this embodiment employs a cleaner-free method, i.e., it does not include a cleaning member for removing residual toner from the photosensitive drum 21.

[0064] In the simultaneous development and cleaning method, residual toner from the transfer is collected in the developer container 32 and reused for image formation. However, the control according to this embodiment can also be applied to an image forming apparatus that uses a cleaning component to remove residual toner from the transfer.

[0065] On the other hand, at the point when the photosensitive drum 21 reaches the developing section, the residual toner from the exposure section (image section) attached to the photosensitive drum 21 does not move from the photosensitive drum 21 to the developing roller 31 in the developing section. This is because, since the potential after exposure is a positive polarity (opposite to the normal polarity of the toner) based on the potential (developing voltage) of the developing roller 31, the residual toner charged to the normal polarity remains in the exposure section. The residual toner remaining in the exposure section becomes part of the toner image to be developed in the developing section and is transferred to the recording material P in the transfer section, thereby being removed from the surface of the photosensitive drum 21.

[0066] 4. Control configuration of the image forming apparatus Figure 9 This is a block diagram showing the control configuration of the image forming apparatus 1. The control unit 90, which serves as the control unit of the image forming apparatus 1, includes a central processing unit (CPU) 91 serving as an arithmetic device, a random access memory (RAM) 92 serving as the working area of ​​the CPU 91, and a read-only memory (ROM) 93 serving as a storage unit for storing various programs. The control unit 90 also includes an input / output (I / O) interface 94 serving as an input / output port for connecting to external devices, and an analog-to-digital (A / D) converter 95 for converting analog signals into digital signals.

[0067] The toner remaining amount detection sensor 50 is connected to the input side of the control unit 90.

[0068] The operation unit 300 and the image forming unit 10 are connected to the control unit 90. The operation unit 300 includes a display unit 301 capable of displaying various setting screens and an input unit 302 such as physical keys. The display unit 301 includes, for example, a liquid crystal panel. The image forming unit 10 includes a drive motor M1 serving as a drive source for driving the photosensitive drum 21, the developing roller 31, the supply roller 33, the stirring member 34, etc. In this embodiment, the drive motor M1 is configured as a common drive source for the drive units driving the photosensitive drum 21, the developing roller 31, the supply roller 33, the stirring member 34, etc., but the drive units are not limited to this. For example, a first drive unit driving the stirring member 34 and a second drive unit rotating the developing roller 31 can be provided separately. In addition, a common drive source for the photosensitive drum 21 and another rotatable member can be provided, for example, a common drive source for the photosensitive drum 21 and the stirring member 34. The control unit 90 is electrically connected to the components of the image forming apparatus 1 (various drive devices M1, various power supplies E1, E2 and E3, various sensors, etc.). The control unit 90 controls the operation of each component by communicating with the components of the image forming apparatus 1.

[0069] The control unit 90 performs an image forming operation by controlling the components of the image forming apparatus 1 based on signals (e.g., image forming start signal, image signal) input from an external device (not shown) such as a personal computer, according to the operation performed by the operator.

[0070] 5. Toner preparation and refilling procedures Next, the configuration related to toner replenishment will be described.

[0071] According to this embodiment, the image forming apparatus 1 detects a low toner remaining amount when the toner remaining amount decreases due to image formation on the recording material P and Y is greater than a second threshold Tth, which is an indicator of a predetermined amount. Here, Y represents what will be described below. Figure 10 The ON time is within a cycle time Ta (1.0 second). That is, when the toner dosage in the developer container 32 is detected to be less than a predetermined threshold, a display is executed on the display unit 301 to prompt the user to perform toner replenishment. In this embodiment, when the user performs toner replenishment, the remaining toner amount is detected for the replenished toner, and the remaining toner amount after replenishment is also detected. The toner stop filling operation (e.g., used as a toner replenishment operation) that is a feature of this embodiment will be described in detail below. According to embodiments of this disclosure, the toner stop filling operation and the drive operation are referred to as the first operation and the second operation, respectively.

[0072] Figure 3 This is a perspective view of the image forming apparatus 1 according to this embodiment. Figure 4AThis is a perspective view showing the developer container 32 and toner packet 40 used as refill containers. Figure 4B This shows the developer container 32 and the toner packet 40. (Example) Figure 3 , Figure 4A and Figure 4B As shown, the image forming apparatus 1 according to this embodiment employs an external replenishment method (direct replenishment method), which uses a replenishment container 40 to replenish toner from outside the apparatus to the developer container 32 inside the apparatus. That is, during replenishment, the operator supplies toner to the developer container 32 inside the apparatus by attaching the toner packet 40, which serves as the replenishment container, to a replenishment protrusion 57 (attachment portion) exposed outside the image forming apparatus 1. In this embodiment employing the direct replenishment method, as... Figure 3 As shown, an opening / closing member 83 for replenishing toner from the toner pack 40 (developer replenishment container) is provided on the discharge tray 81 in an openable and closable manner. A body-side replenishment opening 82 with an upward opening is formed in the discharge tray 81. The opening / closing member 83 is configured to move between a closed position and an open position. In the closed position, the replenishment port 32a (developer receiving port) is covered, preventing the toner pack 40 from being attached to the developer container 32. In the open position, the replenishment port 32a is exposed, allowing the toner pack 40 to be attached to the developer container 32. In the closed position, the opening / closing member 83 functions as part of the discharge tray 81. The opening / closing member 83 and the body-side replenishment opening 82 are formed on the left side of the discharge tray 81.

[0073] Reference Figure 4A and Figure 4B The construction of the developer container 32 and the toner packet 40 is described.

[0074] like Figure 4A and Figure 4B As shown, the developer container 32 includes a protrusion 38 that protrudes upward from one end along its long side and toward the front of the device. At the upper end (front end) of the protrusion 38, an attachment portion 57 is provided for attaching a toner pack 40, and a replenishment port 32a for replenishing developer from the toner pack 40 into the developer container 32 is formed in the attachment portion 57. The replenishment port 32a opens to the outside of the developer container 32 and communicates with an inlet 32c (storage chamber opening) that opens on the inner wall of the toner storage chamber 32d in the developer container 32. That is, a toner replenishment path extending from the replenishment port 32a to the inlet 32c is formed within the protrusion 38, and the replenishment port 32a and the inlet 32c are configured to communicate with each other. In this embodiment, the attachment portion 57 including the replenishment port 32a is arranged on the front side of the image forming apparatus 1 to facilitate the user's toner replenishment operation of the developer container 32.

[0075] The toner cartridge 40 is configured to be attachable to and detachable from an attachment portion 57 located at the front end of a protrusion 38 of the developer container 32. Furthermore, the toner cartridge 40 includes a gate member 41 located at an opening and capable of being opened and closed, and a plurality of protrusions 42 formed corresponding to a plurality of grooves 32b formed in the attachment portion 57. The gate member 41 is configured to be movable between an open position (open) and a closed position (closed).

[0076] When a user supplies toner to the developer container 32, the toner pouch 40 is positioned such that the protrusion 42 passes through the groove 32b of the attachment portion 57, and the toner pouch 40 is coupled to the attachment portion 57. Then, when the toner pouch 40 is rotated 180 degrees in this state, the gate member 41 of the toner pouch 40 abuts against the abutment portion (not shown) of the attachment portion 57, thereby rotating relative to the toner pouch 40 body and opening the gate member 41. Therefore, the toner stored in the toner pouch 40 leaks from the toner pouch 40, and the leaked toner enters the developer container 32 via the replenishment port 32a. The gate member 41 may be located on the replenishment port 32a side.

[0077] Because the toner stored in toner packet 40 is a powder, the toner may clump together within toner packet 40. Therefore, as... Figure 5 As shown, when using the toner packet 40, the user should shake the toner packet 40 thoroughly and manually loosen the toner before use.

[0078] In this embodiment, the refill container includes a deformable plastic bag, but the refill container is not limited to this. For example, the refill container may include a bottle container having a generally conical or generally cylindrical shape. Furthermore, for example, the refill container may include a paper container made of paper. Additionally, as a method of discharging toner from the refill container, if the refill container is a toner packet 40 as in this embodiment or a paper container, the operator can squeeze the refill container by hand; and if the container is a bottle container, it is desirable for the operator to discharge the toner while shaking the container (e.g., tapping it). Furthermore, the bottle container may be provided with a discharging mechanism for discharging toner from the refill container. Furthermore, the discharging mechanism may be configured to engage with a drive mechanism provided on the device body of the image forming apparatus 1 and receive drive from the drive mechanism.

[0079] When the user is performing a supplementary operation, the image forming apparatus 1 performs a toner stop filling operation as a first operation (described below). That is, the toner stop filling operation as a first operation is performed during the interval from when the user moves the open / close member 83 to the open position to when the user moves the open / close member 83 to the closed position.

[0080] After the user completes the toner replenishment operation, i.e., after the image forming apparatus 1 completes the toner stop filling operation, the control unit 90 executes control to perform a drive operation as a second operation. By executing the drive operation as a toner replenishment operation through the control unit 90, the stirring member 34 in the developer container 32 rotates, and the toner replenished from the replenishment port 32a is supplied toward the developing roller 31 and the supply roller 33. Although the replenishment port 32a and the protrusion 38 are arranged at one end in the long side direction of the developer container 32, the toner diffuses throughout the entire area of ​​the developer container 32 through repeated rotation of the stirring member 34. On the other hand, in the toner stop filling operation, toner is replenished while the stirring member 34 and the developing roller 31 are stopped rotating.

[0081] Reference Figure 6 Describe the positional relationship between the toner supply path of the developer container 32 and the scanner unit 11. Figure 6 It is a schematic plan view showing the positional relationship between the scanner unit 11, the supplement port 32a and the inlet 32c of the developer container 32, and is a plan view along the scanning optical path of the laser L of the scanner unit 11.

[0082] The scanner unit 11 includes a light source 110, an aperture 111, an incident optical element 112, a deflector 113, and an imaging optical element 114. The light source 110 is, for example, a semiconductor laser.

[0083] Aperture 111 has an elliptical opening and adjusts the diameter of the light flux emitted from light source 110 in the main scanning direction and sub-scanning direction. Incident optical element 112 has positive refractive power in the main scanning section and converts the light flux passing through aperture 111 into a parallel light flux in the main scanning section. Scanner unit 11 reduces the refractive power required by imaging optical element 114 by converting the light flux that has passed through aperture 111 into a weakly converged light flux. Furthermore, incident optical element 112 has positive refractive power in the sub-scanning section and forms a linear image elongated in the main scanning direction by converging the light flux passing through aperture 111 to the vicinity of deflection surface 113a of deflector 113 in the sub-scanning section.

[0084] Imaging optics 114 exhibits positive refractive power in both the main scanning section and the sub-scanning section. By converging the luminous flux deflected by deflector 113 onto both the main and sub-scanning sections, imaging optics 114 forms a dot-like image near the scanning surface of the photosensitive drum 21. Specifically, imaging optics 114 has two optical surfaces (lens surfaces), namely an incident surface and an exit surface, and is configured such that the luminous flux deflected by the deflection surface 113a of deflector 113 scans the scanning surface of the photosensitive drum 21 in the main scanning section with desired scanning characteristics. Furthermore, in the sub-scanning section, imaging optics 114 places the vicinity of the deflection surface 113a of deflector 113 and the vicinity of the scanning surface of the photosensitive drum 21 in a mutually conjugate relationship. This enables tilt correction compensation (i.e., reducing the scanning position deviation in the sub-scanning direction on the scanning surface of the photosensitive drum 21 when the deflection surface 113a is tilted).

[0085] Thus, the light flux emitted from the light source 110 passes through the aperture 111 and the incident optical element 112, and then enters the deflection surface 113a of the deflector 113. The light flux reflected and deflected by the deflection surface 113a of the deflector 113 is then guided by the imaging optical element 114 to the scanning surface of the photosensitive drum 21. The deflector 113 is rotated at a fixed speed by a drive unit (not shown) and optically scans the scanning surface of the photosensitive drum 21 along the main scanning direction indicated by arrow D, thereby forming an electrostatic latent image on the scanning surface of the photosensitive drum 21.

[0086] like Figure 6 and Figure 1 As shown, the protrusion 38 of the developer container 32 (the toner supply path from the replenishment port 32a to the inlet 32c) extends above and below the scanning optical path of the laser L of the scanner unit 11 at a position that avoids the scanning optical path. That is, when viewed from the left-right direction of the device, the replenishment port 32a is located above the scanning optical path of the laser L, and the inlet 32c is located below the scanning optical path of the laser L. The left-right direction of the device is a direction substantially parallel to the rotation axis of the rotatable components (such as the photosensitive drum 21, the developing roller 31, the supply roller 33, and the stirring component 34).

[0087] In addition, such as Figure 6 As shown, the toner replenishment path from replenishment port 32a to inlet 32c is located inside the end of the photosensitive drum 21 (the center side of the photosensitive drum 21) in the left-right direction of the device. Furthermore, in the front-back direction of the device, the toner replenishment path is located within the space between the photosensitive drum 21 and the scanner unit 11. That is, the protrusion 38 of the developer container 32 is arranged so as not to increase the device size in the left-right and front-back directions, while avoiding the scanning optical path of the laser L emitted from the imaging optics element 114.

[0088] 6. Configuration of the toner remaining amount detection sensor and the method for detecting the toner remaining amount. Reference Figures 7A to 9 The configuration of the toner remaining amount detection sensor 50 according to this embodiment and the method for detecting the toner remaining amount are described. Figures 7A to 7C This is a diagram showing the light guide 600 of the toner remaining amount detection sensor 50. Figure 7A This shows the installation as viewed from the rear side. Figure 1 A cross-sectional view of the B-B' surface of the developer container 32 in the image forming apparatus 1 shown. Figure 7B and Figure 7C This is a perspective view of the light guide 600. Furthermore, Figure 8 This is a circuit diagram showing an example of the circuit configuration of the toner remaining amount detection sensor 50. Figure 9 This is a block diagram showing the control system of the image forming apparatus 1. In this embodiment, a light-transmitting residual amount detection method is used to detect the residual amount of toner, but the detection method is not limited to this. The detection method only needs to be able to identify the change in the residual amount of toner over time. For example, a toner residual amount detection method based on residual electrostatic charge detection or a toner residual amount detection method based on weight measurement can be used.

[0089] like Figures 7A to 7C As shown, in this embodiment, the light guide 600 included in the toner remaining amount detection sensor 50 is installed at the center portion of the developing roller 31 in the direction of its rotation axis. The light guide 600 includes a light incident portion 611 and light path surfaces 612 and 622. The light incident portion 611 introduces light from the light-emitting unit 52 into the light guide 600 outside the developing container 32, and the light path surfaces 612 and 622 generate a light path Q inside the developing container 32. Furthermore, the light guide 600 includes a light emitting portion 621 for transmitting light passing through the light path Q in the developing container 32 to the light receiving unit 53. The light guide 600 is made of polystyrene with an amorphous structure and high transparency.

[0090] like Figure 8As shown, the light-emitting unit 52 uses an LED as the light-emitting element, and the light-receiving unit 53 uses a phototransistor activated by the light from the LED as the light-receiving element. A switch (not shown) is provided between the light-emitting unit 52 and the power supply voltage Vcc, and by turning on the switch, a voltage from the power supply voltage Vcc is applied to the light-emitting unit 52, and the light-emitting unit 52 enters a conducting state. On the other hand, a switch (not shown) is also provided between the light-receiving unit 53 and the power supply voltage Vcc, and by turning on the switch, the light-receiving unit 53 enters a conducting state with a current corresponding to the detected light intensity. For example, a halogen lamp or fluorescent lamp can be used for the light-emitting unit 52, and a photodiode or avalanche photodiode can be used for the light-receiving unit 53.

[0091] The power supply voltage Vcc and the current-limiting resistor R1 are connected to the light-emitting unit 52, and the light-emitting unit 52 emits light through the current determined by the current-limiting resistor R1. Figure 7B As shown, the light emitted by the light-emitting unit 52 passes through the optical path Q and is received by the light-receiving unit 53. The power supply voltage Vcc is connected to the collector terminal of the light-receiving unit 53, and the sensing resistor R2 is connected to the emitting terminal. The light-receiving unit 53, acting as a phototransistor, receives the light emitted from the light-emitting unit 52 and sends (outputs) a signal (current) with an intensity corresponding to the amount of light received. This signal is converted into a voltage V1 by the sensing resistor R2 and input to the A / D conversion unit 95 of the control unit 90 (see...). Figure 9 ).

[0092] The CPU 91 of the control unit 90 determines whether the light receiving unit 53 has received light from the light emitting unit 52 based on the level of the input voltage. Based on the duration and intensity of light detected by the light receiving unit 53 when the toner in the developer container 32 is stirred by the stirring member 34 for a fixed time, the CPU 91 of the control unit 90 calculates the toner dosage (developer dosage) in the developer container 32. That is, the ROM 93 pre-stores a table that can output the remaining toner amount based on the light receiving time and light intensity when the stirring member 34 transfers the toner, and the control unit 90 predicts / calculates the remaining toner amount based on the input to the A / D conversion unit 95 and the table.

[0093] More specifically, the time period during which the light path Q is blocked by the toner delivered by the stirring member 34 when the stirring member 34 rotates once, i.e., the time period during which the light receiving unit 53 does not detect light from the light emitting unit 52, varies depending on the amount of toner remaining. Furthermore, the intensity of the light received by the light receiving unit 53 also varies depending on the remaining amount.

[0094] In other words, compared to the case where the remaining toner is large, when the remaining toner is small, the light receiving unit 53 receives light for a longer time, and the intensity of the light received by the light receiving unit 53 is also higher. The control unit 90 can determine the remaining toner level based on this light receiving time and the intensity of the light received by the light receiving unit 53.

[0095] Next, the voltage waveform and residual quantity detection method of the optical received signal based on the optical receiving unit 53 will be described.

[0096] Reference Figure 10 (A) and Figure 10 Section (B) describes a method for detecting the amount of toner remaining according to this embodiment. Figure 10 (A) and Figure 10 (B) is a cross-sectional image showing the cleaning component 34f about to pass through the toner remaining amount detection sensor 50, and a waveform of the voltage value obtained by converting the light received signal of the light receiving unit 53 through the A / D conversion unit 95. The timing F in the voltage value waveform corresponds to the timing of the cleaning component 34f about to pass through the toner remaining amount detection sensor 50 in the cross-sectional image. Figure 10 Image (A) shows a case where the toner level is full, such as when the toner concentration in developer container 32 is high. Figure 10 Image (B) shows a case where the toner level is low, such as when the developer dosage in developer container 32 is small. The shaded area in the cross-sectional image schematically shows the toner present in developer container 32.

[0097] In this embodiment, the maximum voltage value obtained by converting the optical signal received by the optical receiving unit 53 through the A / D conversion unit 95 is 3.3V. The time during which a voltage of 1V or higher is detected is the ON time, and the time (period) during which a voltage less than 1V is detected is the OFF time (OFF period). Then, a method is used to determine the remaining amount of toner based on the ON time within a cycle time Ta corresponding to one rotation of the stirring member 34. In this embodiment, the cycle time Ta for one rotation of the stirring member 34 is 1.0 second. When the ON time in time Ta is longer, the remaining amount of toner is determined to be smaller, and when the ON time is shorter, the remaining amount of toner is determined to be larger. In this embodiment, the remaining amount of toner is detected based on the ON time within a cycle time Ta; however, the detection method is not limited to this method. For example, the remaining amount of toner can be calculated based on the ratio or proportion of the ON time to the OFF time within a cycle time Ta.

[0098] Figure 10The toner level shown in (A) corresponds to a state with a large toner dosage, and the toner surface is always located above the light guide 600 of the toner remaining amount detection sensor 50. Therefore, the light receiving unit 53 only receives light when the cleaning member 34f cleans the optical path surfaces 612 and 622 of the light guide 600, resulting in an ON time of Tf1. However, the state changes to OFF time immediately after the cleaning member 34f passes. This is because the toner present near the light guide 600 of the toner remaining amount detection sensor 50 immediately blocks the light path Q. In this embodiment, the ON time Tf1 is 0.1 to 0.2 seconds. Figure 10 (The arrow in section (A) indicates that the toner level is full when the ON time within one cycle time Ta (1.0 seconds) decreases to between 0.1 and 0.2 seconds. When "Tfth" is defined as the threshold for a full toner level as described above, and "Y" is defined as the ON time within one cycle time Ta (1.0 seconds), Tfth > Y indicates that the developer container 32 is fully filled with toner. In this embodiment, the threshold Tfth is set to 0.2 (s). The threshold is not limited to Tfth = 0.2 and can be set arbitrarily.

[0099] In such Figure 10 When the toner level is low, as shown in (B), the ON time is longer than when the toner level is full because the toner dosage is small and the photoconductor 600 of the toner remaining detection sensor 50 is not blocked for a longer period. In this embodiment, the ON time when the toner level is low is Figure 10 The total time from Tlow1 to Tlow3, indicated by the arrow in (B), is 0.6 to 0.7 seconds. On the other hand, the OFF time is determined by the timing of the cleaning member 34f, the timing of the toner conveyed by the stirring member 34 blocking the light guide 600 of the toner remaining quantity detection sensor 50, etc. According to this embodiment, the phase detection of the stirring member 34 is performed by reading these OFF times, and the specific method will be described below in the section "Voltage Waveform of the Light Received Signal Based on the Light Receiver Unit 53 and Phase Detection of the Stirring Member". In this embodiment, when the ON time within one cycle time Ta (1.0 seconds) is 0.6 to 0.7 seconds, the toner level is determined to be low. As described above, when "Tlth" is defined as the threshold for a low toner level, and the ON time within one cycle time Ta (1.0 seconds) is defined as "Y", that is, when Tlth < Y, it means that the toner in the developer container 32 has become low. In this embodiment, the threshold Tlth is set to 0.7 (s). The threshold is not limited to Tlth=0.7; it can be set arbitrarily, as long as Tfth≤Tlth.

[0100] In this embodiment, although two toner levels, full and low, are provided as toner levels, only one level, low, may be provided, or multiple levels may be provided additionally. Specifically, toner levels of medium and toner exhaustion may be provided additionally.

[0101] 7. Toner replenishment operation according to this embodiment Next, the toner stopping operation will be described, which is a toner replenishment operation performed by stopping the rotation of the stirring member 34. According to this embodiment, the toner stopping operation is used as a first operation.

[0102] In an image forming apparatus where the developer container 32 is not filled with toner, for example, when the image forming apparatus 1 is new, a toner stopping operation is performed. Thus, an operation that performs a toner replenishment operation when the rotation of the stirring member 34 has stopped is defined as a toner stopping operation. The toner stopping operation is an example of the replenishment operation described above and can be included as part of a replenishment operation. Similar to the replenishment operation, the toner stopping operation includes, for example... Figure 5 The user operation involves kneading the toner packet 40, connecting the toner packet 40 to the replenishment port 32a, and filling the developer container 32 with the toner from the toner packet 40 through the replenishment port 32a. In the drive operation, which is performed as a second operation after the toner filling stop operation, the rotation of the stirring member 34, the developing roller 31, and the supply roller 33 begins immediately after replenishment, and the replenished toner diffuses throughout the entire area of ​​the developer container 32. Conversely, in the toner filling stop operation, the rotation drive of the stirring member 34, the developing roller 31, and the supply roller 33 begins after the toner remaining quantity detection sensor 50 detects that the toner filling has stopped and is in a drive-stopped state. Activating this drive only after detecting the toner filling stop operation prevents damage to the developing roller 31, the developing blade 35, and the supply roller 33 due to friction between the developing blade 35 and the supply roller 33 and the developing roller 31 when no toner is present.

[0103] The following section describes the detection method for when the toner stops filling and the procedures to be performed before and after the detection.

[0104] In this embodiment, the control unit 90 performs control to perform toner stop filling detection when the toner stop filling operation is performed using the toner remaining amount detection sensor 50.

[0105] As described above, the toner remaining amount detection sensor 50 is a sensor that detects the remaining amount of toner in the developer container 32 by referring to a changing output value while the toner in the developer container 32 is stirred by the stirring member 34. Toner stop filling detection can be performed without driving the stirring member 34 by executing the following detection process. In the following text, reference will be made to... Figure 11 Describe the detection operation.

[0106] (1) The toner stops filling during the executable period from Topen to Tclose. Before performing the toner stop-fill operation, the user moves the open / close component 83 to the open position. Then, the toner pack 40 is inserted into the refill port 32a, and the toner stop-fill operation begins. After the toner stop-fill operation is complete, the user removes the toner pack 40 from the refill port 32a and moves the open / close component 83 to the closed position. Figure 11 As shown, the time it takes for the opening / closing component 83 to move to the open position is defined as "Topen", and the time it takes for the opening / closing component 83 to move to the closed position is defined as "Tclose". The time from time Topen to time Tclose is the period during which the toner stopping filling operation can be performed, and this period is defined as the toner stopping filling executable period. By detecting the time "Topen" and time "Tclose" as triggers for each control, the control unit 90 can perform control. The detection of the time "Topen" and time "Tclose" is achieved by a switch, etc., for example, the switch is energized together with the opening / closing of the opening / closing component 83 and sends a signal to the control unit 90. That is, the control unit 90 detects information indicating that the opening / closing component 83 is in the open position, and then detects information indicating that the opening / closing component 83 is in the closed position.

[0107] (2) Monitor the output value of the toner remaining amount detection sensor during the period when toner filling is stopped. During the toner refill stop period from time Topen to time Tclose, the control unit 90 activates the toner remaining quantity detection sensor 50 to monitor the output value and detect information regarding whether a toner refill stop operation has occurred. Specifically, the toner remaining quantity detection sensor 50 detects information about the toner and monitors whether the toner refill stop operation has been executed correctly.

[0108] Figure 11The diagram shows an example waveform of the voltage value V(t) (first value) obtained by converting the light received signal from the light receiving unit 53 via the A / D conversion unit 95 when the toner filling operation stops. Time Tstart is the actual start time of the toner filling operation, and time Tend is the actual end time of the toner filling operation. (The diagram shows the waveform of the voltage value V(t) obtained by converting the light received signal from the light receiving unit 53 via the A / D conversion unit 95.) Figure 11 As shown in the waveform, in this experiment, the flow rate of toner from toner packet 40 into developer container 32 remained constant during the time interval from time Tstart to time Tend. The image forming apparatus 1 does not detect the start and end times (Tstart and Tend) of the toner stop-fill operation. These are in... Figure 11 The voltage waveform is used only for explanation. In this embodiment, the image forming apparatus 1 is configured not to detect the start and end times (Tstart and Tend) of the toner stop filling operation, but the configuration is not limited to this. For example, the control unit 90 arranged in the image forming apparatus 1 can use a detection unit to detect the start and end of the toner stop filling operation.

[0109] The toner filled into the developer container 32 blocks the light path when it reaches the vicinity of the toner remaining quantity detection sensor 50, which serves as an optical detection sensor unit. Therefore, the amount of light detected by the toner remaining quantity detection sensor 50 is reduced. When the sensor output value Vend (the first value at time Tclose) at time Tclose is lower than a first threshold Vth1, the toner is detected as fully filled by the toner stopping operation. In this embodiment, Vth1 is set to 1V. This allows the detection of the toner stopping operation to be performed without driving the stirring member 34. Here, detecting the toner stopping operation also includes controlling whether the toner stopping operation has actually been performed. Furthermore, detecting the toner stopping operation also includes controlling whether to switch to the next replenishment operation, i.e., whether to rotate the stirring member 34, when the output value Vend exceeds the threshold Vth1, rather than directly determining whether the toner stopping operation has been detected or not. Furthermore, instead of referencing the sensor output value Veng at time point Tclose, a toner filling stop operation can be determined if the output value Vend repeatedly exceeds the first threshold Vth1, or if the output value Vend remains below the first threshold Vth1 for a certain period of time. Alternatively, a toner filling stop operation can be determined if the difference between the output value V and the output value Von at time ON exceeds a threshold. In other words, it is important that the sensor output value V changes and exceeds the threshold Vth when a toner filling stop operation is determined to have been detected.

[0110] Furthermore, in this embodiment, when the image forming apparatus 1 (i.e., the developer container 32) is new, it is desirable to perform a toner stop-filling operation. If the toner is stored in the developer container 32, the toner stop-filling operation can be omitted. That is, in toner replenishment operations performed in states other than the new state, some toner is present near the stirring member 34 and the developing roller 31, so the replenishment operation can be performed while driving the stirring member 34 and the developing roller 31.

[0111] In this embodiment, the case where the output value of the toner remaining amount detection sensor 50 is output as a voltage has been described; however, the physical quantity to be output is not limited to voltage. For example, the values ​​Vend and Vth1 described above can more generally be represented as the values ​​Send and Sth1 as detection signals.

[0112] (3) Phase of the stirring component Figures 12A to 12D This is a diagram showing a cross-sectional view of the developer container 32 and the toner remaining quantity detection results when a toner stop-filling operation is performed on the developer container 32 with a different phase from the stirring member 34. Specifically, Figures 12A to 12D The diagrams are cross-sectional images of the developer container 32 in a left-right direction perpendicular to the toner remaining amount detection sensor 50, a transmission image of the developer container 32 viewed from the front, and a diagram showing the voltage waveform obtained by the A / D conversion unit 95 converting the light receiving signal of the light receiving unit 53 when filling stops.

[0113] During each toner refill stop operation, the flow rate of toner from toner package 40 into developer container 32 remains constant during the period from time Tstart to time Tend.

[0114] Furthermore, the time interval from time Tstart to time Tend is divided into three equal periods, such as... Figures 12A to 12D As shown, the time periods for switching are defined as T1 and T2.

[0115] In the cross-sectional image, the toner at time Tclose is shown as the upper right shaded pattern (A1). In the transmission image, the toner filling the time interval from time Tstart to time T1 is shown by the upper left shaded pattern (A2), the toner filling the time interval from time T1 to time T2 is shown by the checkered pattern (A3), and the toner filling the time interval from time T2 to time Tend is shown by the upper right shaded pattern (A4).

[0116] Figures 12A to 12D The phases of the stirring component 34 shown in the cross-sectional image are defined as positions 1 to 4.

[0117] Position 1 is the phase where the free end 34be1 of the blade portion 34b of the stirring member 34 is directly below the toner remaining amount detection sensor 50. When the phase of the stirring member 34 is position 1, the toner to be filled accumulates in the developer container 32 as follows: First, during the time period from time Tstart to time T1, as... Figure 12A As shown, the toner is blocked by the blade portion 34b of the stirring member 34 and accumulates in the area directly below the replenishment port 32a, which is indicated by the shaded pattern (A2) in the upper left of the transmission image. At this stage, there is no toner near the toner remaining amount detection sensor 50, and as can be seen from the diagram showing the voltage waveform, light continues to transmit near the toner remaining amount detection sensor 50. Therefore, the toner remaining amount detection sensor 50 continues to detect light. Next, from time T1 to time T2, the toner to be filled is blocked by the blade portion 34b of the stirring member 34 and accumulates in the area shown by the grid pattern (A3) in the transmission image. The grid pattern (A3) in the transmission image overlaps with the toner remaining amount detection sensor 50, and it can be seen that during the time period from time T1 to time T2, the toner has filled to the position of the toner remaining amount detection sensor 50. Figure 12A The voltage waveform diagram also shows that during the time period from time T1 to time T2, the amount of light detected by the toner remaining amount detection sensor 50 has decreased, and the output drops below the first threshold Vth1. Finally, during the time period from time T2 to time Tend, the filled toner accumulates in the area shown by the shaded pattern (A4) in the upper right corner of the transmission image diagram. At this time, the toner remaining amount detection sensor 50 is embedded in the toner, and its output value remains unchanged during the time period from time T2 to time Tend. As can be seen from the diagram showing the voltage waveform, at time Tclose, the sensor output value drops below the first threshold Vth1, and the control unit 90 detects that the toner stopping filling operation has been performed, that is, the toner has been fully replenished into the developer container 32.

[0118] Positions 2, 3, and 4 are the phases of the stirring component 34, which advance clockwise by 90°, 180°, and 270° relative to position 1, respectively.

[0119] When the stirring member 34 is in phase 2, similar to phase 1, the filled toner is blocked by the blade portion 34b of the stirring member 34 and accumulates in the developer container 32. However, the amount of toner required to fill to the position of the toner remaining amount detection sensor 50 when the phase is position 2 is greater than the amount of toner required when the phase is position 1. Therefore, even if the toner filling stop operation is performed, similar to position 1, the output value of the toner remaining amount detection sensor 50 takes time to drop below the first threshold Vth1. From the transmission image diagram and Figure 12B As can be seen from the voltage waveform diagram shown, at time T2, i.e. later than position 1, the toner remaining amount detection sensor 50 is blocked by the filled toner.

[0120] When the stirring component 34 is in phase 3, such as Figure 12C As shown, the filled toner accumulates in the developer container 32 without being blocked by the stirring member 34. Then, if the toner has filled to the position of the toner remaining detection sensor 50, the amount of light detected by the toner remaining detection sensor 50 decreases, and the output drops below the first threshold Vth1. The amount of toner required to fill the position of the toner remaining detection sensor 50 is even greater than the amount of toner required at phase position 2. Therefore, in the time between time T2 and time Tend, i.e., later than position 2, the toner remaining detection sensor 50 is blocked by the filled toner.

[0121] When the stirring component 34 is in phase 4, such as Figure 12D As shown in the cross-sectional image, the stirring member 34 prevents the filled toner from reaching the position of the toner remaining amount detection sensor 50. Therefore, since the output value of the toner remaining amount detection sensor 50 will not fall below the first threshold Vth1 even at time point Tclose, the control unit 90 cannot detect information about the toner filling operation stopping.

[0122] As described above, the minimum amount of toner required to detect information about the toner stopping operation increases sequentially from phase position 1 to position 3 of the stirring member 34. On the other hand, there is also a stirring phase similar to position 4, at which information about the toner stopping operation cannot be detected.

[0123] In other words, by appropriately setting the phase of the stirring member 34 during toner level detection, the minimum toner filling amount required for detecting information regarding the toner stop filling operation can be ideally set. The minimum toner filling amount required for detecting information regarding the toner stop filling operation only needs to be a toner dosage sufficient to sufficiently avoid damage caused by friction between the developing doctor blade 35 and the supply roller 33 and the developing roller 31 during operation. That is, a larger amount can be set depending on the construction of the image forming apparatus 1 and various conditions. In this embodiment, by performing the detection of information regarding the toner stop filling operation during the stirring phase at position 1, damage to various components due to friction can be effectively avoided. Furthermore, by setting the stirring phase at position 2 or position 3, the minimum toner filling amount suitable for detecting information regarding the toner stop filling operation increases compared to position 1. However, by appropriately setting this amount, the toner stop filling operation can be performed at any of these positions. This also applies to position 4, and the minimum toner filling amount can be set according to position 4.

[0124] In this way, the minimum toner fill amount can be set according to the stirring phase. For example, a minimum toner fill amount can be set that allows for the detection of sufficient toner dosage to prevent various image defects during image formation. Furthermore, the minimum toner fill amount can be set using the intended toner pack 40, which allows for the detection of the intended toner dosage in the event that all toner in the pack is consumed during the toner stop-filling operation. That is, it can be said that position 1 is effectively used when the volume of the developer container 32 is relatively small, while positions 3 and 4 are effectively used when the volume of the developer container 32 is relatively large. Therefore, the setting of the minimum toner fill amount based on these stirring phase settings can be appropriately modified according to the construction of the apparatus to which this disclosure is applied and various conditions. Furthermore, the design can assume the most difficult construction conditions for toner detection, regardless of the volume of the developer container 32 and the stirring phase.

[0125] So far, the following scenario has been described: the flow rate of toner from toner packet 40 into developer container 32 remains constant from time Tstart to time Tend, and a toner stop filling operation is performed.

[0126] However, when detecting information regarding the toner refill stop operation as described above, the flow rate at the time of the toner refill stop operation does not need to be constant. For example, in irregular flow rate changes caused by manual operation by the user, the time it takes for the toner to reach and block the toner remaining amount detection sensor 50 becomes uncertain. However, since the required minimum toner filling amount remains constant, the detection of information regarding the toner refill stop operation can be performed based on the toner remaining amount detection.

[0127] Furthermore, for example, the phase of the stirring member 34 can be set during the assembly of the image forming apparatus 1 by setting its phase during assembly.

[0128] Next, the detection of remaining toner quantity (as the second detection) performed after information about the toner filling operation being detected (as the first detection) will be described.

[0129] In this embodiment, after detecting information regarding the toner refill stop operation, a drive operation, serving as a second operation, is initiated. This drive operation includes rotation of the stirring member 34, the developing roller 31, and the supply roller 33. The toner refill stop operation and the drive operation can be collectively defined as a toner replenishment operation, or each can be defined as a toner replenishment operation. In this drive operation, the remaining toner level is detected using a toner remaining amount detection sensor 50. As described above, according to Figure 10 (A) and Figure 10 The method shown in (B) controls and performs the detection of the remaining amount of toner by the control unit 90 based on the ON time within one cycle time Ta of one rotation of the stirring member 34.

[0130] based on Figure 13 The flowchart shown describes the series of operations to be performed before and after the toner filling operation is stopped.

[0131] First, in step S1, the control unit 90 detects information indicating that the opening / closing component 83 has been moved to the open position by the user moving the opening / closing component 83 to the open position. In step S1, the control unit 90 detects this information at time Topen. Therefore, in the subsequent step S2, the control unit 90 begins detecting toner information regarding the toner stop-filling operation at time Topen. While performing this toner information detection, the user attaches the toner pack 40 to the replenishment port 32a and supplies toner from the toner pack 40 towards the developer container 32. If the user determines that toner has been adequately replenished from the toner pack 40 into the developer container 32, the user removes the toner pack 40 from the replenishment port 32a and moves the opening / closing component 83 to the closed position. In step S3, the user moves the open / close component 83 to the closed position. The control unit 90 detects the closed position of the open / close component 83 at time Tclose. In step S4, the control unit 90 performs control by ending the detection of toner information regarding the toner stop filling operation.

[0132] In step S5, the control unit 90 determines whether toner information regarding the toner stop filling operation has been detected. When the output value Vend detected by the toner remaining amount detection sensor 50 at time point Tclose is lower than the threshold Vth1 ("Yes" in step S5), the toner filling operation has been sufficiently performed by the toner stop filling operation, and therefore the control unit 90 performs control in a manner that executes subsequent drive operations. That is, based on information about the toner used as developer, in the toner stop filling operation used as toner replenishment operation, the control unit 90 controls the drive motor M1 of the stirring member 34 used as the first drive unit and the drive motor M1 of the developing roller 31 used as the second drive unit. In this embodiment, the drive motor M1 serves as both the first and second drive units. Here, in step S5, it can also be said that the control unit 90 determines whether the toner stop filling operation has been performed. When Vend = X, if it is determined in step S5 that Vth1 < X is satisfied ("Yes" in step S5), the process proceeds to step S7. In step S7, the control unit 90 performs control in a manner that initiates a drive operation including the rotation of the stirring member 34, the developing roller 31, and the supply roller 33. On the other hand, if it is determined in step S5 that Vth1 < X is not satisfied ("No" in step S5), the process proceeds to step S6. In step S6, the control unit 90 performs a display on the display unit 301 to indicate insufficient toner or to suggest toner replenishment. The toner replenishment prompt is a message indicating insufficient toner, such as the message "Printing cannot be performed due to low toner levels. Replenish toner." After the drive operation begins in step S7, in step S8, the control unit 90 performs control in a manner that uses the toner level detection sensor 50 to detect the remaining toner level. Here, the ON time in a cycle time Ta (1.0 second) is defined as "Y". If the toner remaining amount detection sensor 50 detects information indicating that the amount of toner present exceeds a threshold Tth (Tth > Y) ("Yes" in step S9), the process proceeds to step S11. In step S11, the control unit 90 performs control in a manner that executes an initial installation operation. The initial installation operation is a preparation operation for the image forming operation that forms an image on the recording material P, and is an operation that starts the drive motor M1 and executes heating of multiple processing devices involving the rotation drive of the photosensitive drum 21. After performing the initial installation operation in step S11, the control unit 90 performs control in a manner that stops various operations.

[0133] Here, for example, the second threshold Tth can be a value corresponding to a toner dose sufficient to prevent various image defects in the image forming operation. Alternatively, the second threshold Tth can be a value corresponding to the expected toner dose when a toner stop-fill operation is performed using the expected toner pack 40. Here, the second threshold Tth can be determined using a different determination method than the toner remaining amount detection, in which the output value is compared with the first threshold Vth1. Specifically, as described above, the second threshold Tth is determined based on the ON time in a cycle time Ta (1.0 seconds). In this embodiment, the second threshold Tth is set to 0.7 (s). This is the same as the value of the threshold Tlth. If the filled toner dose is approximately equal to a low toner level, it can be determined that even if the drive operation is performed, no damage will be caused to the components, and no image defects will occur. Here, Tlth = Tth does not necessarily need to be set.

[0134] On the other hand, if it is determined in step S9 that Tth > Y is not satisfied ("No" in step S9), the process proceeds to step S10. In step S10, the control unit 90 performs control to stop the drive operation based on the detection result of the remaining toner obtained by the toner remaining amount detection sensor 50. Then, in step S6, as described above, the user is notified of insufficient toner remaining amount through the display on the display unit 301, and the user is prompted to perform toner refill. That is, the control unit 90 performs control in such a way that it performs a display to prompt the user to perform the toner stop refill operation. This can further reduce the possibility of damage to rotatable components (such as the developing roller 31, developing blade 35, and supply roller 33) that may be caused by the drive operation.

[0135] The image forming apparatus according to this embodiment has the following features.

[0136] The image forming apparatus includes a photosensitive drum 21 serving as an image carrier and a developing roller 31 serving as a rotatable developing agent carrier for supplying developing agent to the photosensitive drum 21. The image forming apparatus includes a developing agent container 32 serving as a developing agent storage unit, a rotatable stirring member 34 disposed in the developing agent container 32 and stirring the toner, the developing roller 31, and a drive motor M1 that drives the stirring member 34 to rotate. The developing roller 31 is disposed in the developing agent container 32, which stores the toner used as developing agent. The image forming apparatus includes a toner remaining amount detection sensor 50 disposed in the developing agent container 32, and a developing agent detection unit that detects information about the toner stored in the developing agent container 32. The image forming apparatus includes an attachment portion 57 provided with a replenishment port 32a communicating with the developing agent container 32 and a control unit 90 that controls the drive motor M1. A toner pack 40 serving as a replenishment container is detachably attached to the developing agent container 32. Toner is replenished from the toner package 40 attached to the attachment part 57 into the developer container 32 through the replenishment port 32a, and the replenishment operation is performed while the developing roller 31 and the stirring member 34 are stopped rotating, without performing the rotation operation of the developing roller 31 and the stirring member 34. Then, the control unit 90 controls the drive motor M1 based on information about the toner used for the replenishment operation and the toner stopping the filling operation.

[0137] Furthermore, the drive motor M1 can be a common drive source that rotates both the stirring member 34 and the developing roller 31. In this case, the developing roller 31 is configured to rotate by rotating the stirring member 34.

[0138] The image forming apparatus includes an opening / closing member 83, which is movable to an open position and a closed position. In the open position, the replenishment port 32a is exposed, allowing developer to be replenished from the replenishment container to the developer storage unit. In the closed position, the replenishment port 32a is blocked, preventing developer from being replenished from the replenishment container to the developer storage unit. During the period from detecting information indicating that the opening / closing member 83 is in the open position to detecting information indicating that the opening / closing member 83 is in the closed position, the control unit 90 performs control in a manner that detects information about the developer in the replenishment operation using the toner remaining amount detection sensor 50. When information indicating that the opening / closing member 83 is in the closed position is detected, the control unit 90 performs control in a manner that terminates the control performed by the toner remaining amount detection sensor 50. When information indicating that the opening / closing member 83 is in the open position is detected, the control unit 90 performs control in a manner that begins the control performed by the toner remaining amount detection sensor 50. Based on the information about the developer in the replenishment operation detected when information indicating that the opening / closing member 83 is in the closed position is detected, the control unit 90 controls the drive motor M1. Information regarding the developer in the toner stop-filling operation, used as a toner replenishment operation, refers to a first value V, which is information about the amount of developer stored in the developer container 32. The image forming apparatus includes a ROM 93 serving as a storage unit, storing a first threshold for this first value. If the first value exceeds the first threshold Vth1, the control unit 90 performs control in such a way that, after the toner stop-filling operation as a first operation, it performs a drive operation as a second operation of the rotating stirring member 34. The image forming apparatus includes a display unit 301 that displays information about the toner filled into the developer container 32, and if the first value does not exceed the first threshold, the control unit 90 performs control in such a way that it displays information on the display unit 301 indicating that developer has not yet been replenished into the developer container 32. Alternatively, the control unit 90 performs control in such a way that it displays information prompting the user to replenish the toner from the toner pack 40 into the developer container 32. The ROM 93 stores a second threshold Tth, which is a threshold different from the first threshold. If the first value exceeds the second threshold during the drive operation, the control unit 90 performs control in such a way that an initial installation operation is performed after the drive operation. This initial installation operation serves as a preparation operation to be performed before the image forming operation on the recording material P to form an image. If the first value does not exceed the second threshold, the control unit 90 performs control in such a way that information indicating that toner has not been replenished to the developer container 32 is displayed on the display unit 301. Alternatively, the control unit 90 performs control in such a way that information prompting the user to replenish the toner from the toner pack 40 to the developer container 32 is displayed.

[0139] The toner remaining amount detection sensor 50 includes a light incident section 611 and a light emitting section 621. Light emitted from the image forming apparatus 1 enters through the light incident section 611, and the light emitting section 621 directs the light toward a light receiving unit disposed in the image forming apparatus. The toner remaining amount detection sensor 50 can detect an output voltage, which is a first value corresponding to the light received by the light receiving unit.

[0140] As described above, in this embodiment, by detecting toner information regarding the toner stop filling operation, toner can be detected when the driving of the developing roller 31 and the stirring member 34 is stopped. Then, after the toner stop filling operation is performed, when the developing roller 31, the stirring member 34, etc., are started to be driven, it can be appropriately determined that toner is present in the developing container 32.

[0141] Another embodiment of this disclosure will be described. The basic configuration and operation of the image forming apparatus according to this embodiment are the same as those according to the first embodiment. Therefore, in the image forming apparatus according to this embodiment, components having the same or corresponding functions or configurations as those in the image forming apparatus according to the first embodiment are given the same reference numerals as those in the image forming apparatus according to the first embodiment, and detailed descriptions will be omitted.

[0142] In the toner stop-fill detection performed during the toner stop-fill operation in the first embodiment, for example, the toner packet 40 may contain a relatively large amount of air before toner filling. In this case, the toner dosage near the toner remaining amount detection sensor 50 may be small at time Tclose. In this case, the toner stop-fill detection method based on the sensor output value at time point Tclose described in the first embodiment may fail to detect the toner stop-fill even if it has been performed. In view of the above, this embodiment aims to provide a method that can perform toner stop-fill detection even under the above circumstances.

[0143] 1. Method for determining when toner stops filling Figure 14 The upper part shows an example of the voltage waveform obtained by converting the light receiving signal of the light receiving unit 53 through the A / D conversion unit 95 when the toner filling operation is performed.

[0144] Figure 14 The lower part shows cross-sectional images of the surface of the developer container 32, which includes the toner remaining amount detection sensor 50, in the left-right direction at times T21, T23, and Tclose, as well as a transmission image of the developer container 32 viewed from the front.

[0145] exist Figure 14 During the test, a toner filling stop operation was performed during the period from time Tstart to time Tend. During the period from time Tstart to time T23, the toner filling stop operation was performed such that the toner mainly flowed into the developer container 32. Then, during the period from time T23 to time Tend, the toner filling stop operation was performed such that the fluid obtained by actively mixing the toner and airflow flowed into the developer container 32. The phase of the stirring member 34 was set to the phase corresponding to position 1 described in the first embodiment.

[0146] First, the toner filling operation stops at time point Tstart. The toner is blocked by the blade section 34b of the stirring member 34 and accumulates in the area directly below the replenishment port 32a. At time point T21, the toner is almost non-existent in the detection area of ​​the toner remaining amount detection sensor 50. From... Figure 14 As shown in the voltage waveform, light continues to transmit through the toner remaining amount detection sensor 50, and the output voltage remains unchanged compared to the output voltage before the toner filling operation begins. At time T22, toner filling proceeds further, and the filled toner reaches the position of the toner remaining amount detection sensor 50. Therefore, the amount of light detected by the toner remaining amount detection sensor 50 decreases, and the output voltage drops below the threshold Vth2.

[0147] During the period from time Tstart to time T23, only toner is filled, and the filled toner begins to accumulate directly below the filler port 32a. Then, while being blocked by the blade portion 34b of the stirring member 34, the toner, when viewed from the front... Figure 14 In the transmission image, the diffusion is directed towards the right side of the developer container 32. At time point T23, it can be seen from the cross-sectional image and the transmission image that the toner filled into the developer container 32 covers the toner remaining amount detection sensor 50. Therefore, the output voltage drops below the threshold Vth2. So far, the operation has proceeded in a manner similar to that in the first embodiment.

[0148] On the other hand, during the period from time T23 to time Tend, fluid obtained by mixing toner and air is added to the developer container 32 via replenishment port 32a. Since the air mixes with the toner in the developer container 32, the toner is scattered within the developer container 32 without stable settling. In the detection area of ​​the toner remaining amount detection sensor 50, the light scattered by the toner passes through the optical path of the toner remaining amount detection sensor 50, and the detected light repeatedly has periods of passing through and periods of not passing through. Therefore, during the period from time T23 to time Tend, the voltage waveform fluctuates repeatedly, and after time T24, the output voltage detected by the toner remaining amount detection sensor 50 becomes an output value exceeding the threshold Vth2.

[0149] Referring to the cross-sectional and transmission images at time point Tclose, it can be seen that although sufficient toner has been added to the developer container 32, almost no toner is present in the detection area of ​​the toner remaining amount detection sensor 50. Thus, at time Tclose, there is insufficient toner in the detection area of ​​the toner remaining amount detection sensor 50, which could lead the control unit 90 to erroneously detect that the toner stop filling operation has not been performed, according to the determination method of the first embodiment.

[0150] In view of the above, in this embodiment, when the output value detected by the toner remaining amount detection sensor 50 drops below the threshold Vth2 even once, it is considered that a toner refilling stop operation has been performed. In this embodiment, for example, when it detects... Figure 14 In the case of the voltage waveform shown, since the toner filling operation stops, the output value drops below the threshold Vth2 at time T22, thus determining that the toner remaining amount detection sensor 50 has detected information about the toner filling operation stopping.

[0151] In this embodiment, a description has been given of the case where the output value of the toner remaining amount detection sensor 50 is given as a voltage output, but the physical quantity to be output is not limited to voltage. The aforementioned values ​​V(t) and Vth2 can be more generally represented as S(t), with Sth2 as a signal. Furthermore, in the description of the above embodiment, the voltage value V(t) is described as continuous, but the actual value acquired is a discrete output. Therefore, the voltage value V(t) can be represented as V1, V2, ..., Vn. Furthermore, these can be more generally represented as S1, S2, ..., Sn as signals. The data acquisition interval according to this embodiment is 5 ms.

[0152] As described above, even if the toner stop filling operation has been performed but no information about the toner stop filling operation can be detected, according to this embodiment, there may be cases where information about the toner stop filling operation can be detected. On the other hand, if the toner filling amount is insufficient, performing a drive operation after detecting information about the toner stop filling operation may damage critical components. In view of the above, similar to the first embodiment, it is desirable to perform toner remaining amount detection after detecting information about the toner stop filling operation, and to detect again information indicating that there is a sufficient amount of toner in the developer storage unit.

[0153] In the above description, it is assumed that the toner is filled with a large amount of air, and the state of large fluctuations in the output waveform detected by the toner remaining amount detection sensor 50 has been described. Even under conditions other than those described above, when a toner filling stop operation is performed using a toner pack 40 with less air, there are still cases where the output waveform detected by the toner remaining amount detection sensor 50 fluctuates significantly. For example, this fluctuation may occur when the user squeezes the toner pack 40 forcefully. Furthermore, in the image forming apparatus 1, which has the toner remaining amount detection sensor 50 configured directly below the replenishment port 32a, this waveform is naturally detected.

[0154] Furthermore, this detection method is particularly effective when toner cannot accumulate in the detection area of ​​the toner remaining amount detector 50 due to the positional relationship between the position of the stirring member 34 and the position of the toner remaining amount detection sensor 50.

[0155] In the first and second embodiments, the description primarily assumes that the long side position of the toner remaining amount detection sensor 50 is different from the long side position of the replenishment port 32a. However, according to this embodiment, when the long side position of the toner remaining amount detection sensor 50 is the same as or close to the long side position of the replenishment port 32a, that is, when the toner remaining amount detection sensor 50 is located directly below the replenishment port 32a, the detection accuracy can be further improved. Then, the amount of toner filled can be quantified based on the detection result.

[0156] Furthermore, even if the toner is not filled into the detection area of ​​the toner remaining amount detection sensor 50 after the toner filling operation is performed, and the detection method according to the first embodiment cannot be used, the detection method according to this embodiment can also be used.

[0157] 1. Method for determining when toner stops filling Figure 15The upper part shows an example of the voltage waveform V(t) obtained by converting the light receiving signal of the light receiving unit 53 through the A / D conversion unit 95 when the toner filling operation is performed.

[0158] Figure 15 The lower part shows a cross-sectional image of the developer container 32 in a direction perpendicular to the left and right of the time Tclose, the developer container 32 including the toner remaining amount detection sensor 50, and a transmission image of the developer container 32 as viewed from the front.

[0159] In this embodiment, it is assumed that the replenishment port 32a is located in the central portion of the developing roller 31 along its axial direction (i.e., the long side direction), and the toner remaining amount detection sensor 50 is located directly below the replenishment port 32a, at a higher position than the configuration of the developer container 32 according to the first and second embodiments. In the first and second embodiments, the toner filling and replenishment path is arranged to avoid the laser L of the scanner unit 11. On the other hand, if the replenishment port 32a is located in the central portion as in this embodiment, it is assumed, for example, that the scanner unit 11 is located at the end in the axial direction. Alternatively, a configuration of an LED array in which multiple LEDs are arranged along the axial direction of the photosensitive drum 21 can be considered. In this embodiment, the axial direction of the photosensitive drum 21 and the axial direction of the developing roller 31 are substantially parallel to each other.

[0160] like Figure 15 As shown in the voltage waveform detected by the toner remaining amount detection sensor 50, during the period from time Tstart to time Tend, the detection area of ​​the toner remaining amount detection sensor 50 is blocked by toner according to toner filling, and there is a timing period during which the output value decreases. On the other hand, during the toner stopping operation, the output value becomes larger during periods when the flow rate of toner from the toner package 40 to the developer container 32 is low, or during periods when the toner stopping operation stops. That is, the toner filling amount is related to the value I obtained by integrating the difference between the output voltage Von and the voltage value V(t), where the output voltage Von is the output voltage when there is almost no toner in the detection area of ​​the toner remaining amount detection sensor 50, and the voltage value V(t) is the time from time Topen to time Tclose. In other words, the following relationship expression holds.

[0161] .

[0162] Therefore, in this embodiment, when the value I obtained by integrating the difference between the sensor output value V and the sensor output value Von within the time from time Topen to time Tclose exceeds the threshold Ith3, the detection of information about the toner filling operation is triggered.

[0163] In the description of the above embodiments, the voltage value V(t) is described as continuous, but the actual value obtained is a discrete output. Therefore, the voltage value V(t) can be described as V1, V2, ... Vn. According to this embodiment, the data acquisition interval is 5ms.

[0164] Considering the discrete output values ​​V1, V2, ..., Vn, the value corresponding to the above integral value I is (Von-V1) + (Von-V2) + ... + (Von-Vn) = nVon-(V1+V2+...+Vn). When V1+V2+...+Vn is defined as VSUM, the above expression becomes nVon-VSUM. This value can be compared with a predetermined threshold and used as a criterion for detecting toner stop-filling operation. Furthermore, since the output value Von is a constant, a threshold depending on "n" is defined as VSUMth3, which can be compared with VSUM and used as a criterion for detecting toner stop-filling operation.

[0165] In this embodiment, a description has been given of the case where the output value of the toner remaining amount detection sensor 50 is output as a voltage, but the physical quantity to be output is not limited to voltage. For example, the above values ​​V1, V2, ... and Vn, VSUM and VSUMth3 can be more generally represented as S1, S2, ... and Sn, SSUM and SSUMth3 as signals.

[0166] As described above, according to the detection method of this embodiment, when the position of the toner remaining amount detection sensor 50 in the axial direction is close to or equal to the position of the replenishment port 32a, the toner dosage when the toner filling operation is stopped can be quantified.

[0167] As described above, according to the detection method described in the first to third embodiments, the toner stopping and filling operation can be appropriately performed even when the rotation drive of the developing roller 31 and the stirring member 34 has stopped. Furthermore, a method can be provided that, when a drive operation for driving the developing roller 31, stirring member 34, etc., is performed after the toner stopping and filling operation is detected, it is possible to detect whether there is sufficient toner in the developer container 32.

[0168] Furthermore, needless to say, the determination methods described in the first to third embodiments can be appropriately selected according to the configuration of the apparatus of this disclosure and various conditions, and these methods can be combined for detection.

[0169] So far, the description has primarily focused on the case where the driving sources for the developing roller 31 and the stirring member 34 are the same, and a method for performing toner stop filling detection while stopping the driving of the developing roller 31 and the stirring member 34 during the toner stop filling operation has been described. However, even when the developing roller 31 and the stirring member 34 can be driven separately by individual driving sources, it is naturally possible to stop both driving sources during the toner stop filling operation and perform information detection through the toner stop filling operation described in the first to third embodiments. For example, compared to performing toner filling detection while driving the stirring member 34 during toner filling, performing information detection through the toner stop filling operation without driving the stirring member 34 allows for earlier detection of sufficient toner filling.

[0170] Furthermore, in the first to third embodiments, the toner stopping operation was described assuming that the toner stopping operation was performed and detected when no toner was added to the developer container 32. However, the method can be applied similarly in the direction of toner leakage downwards from the replenishment port 32a, as long as the replenishment port 32a, the toner remaining amount detection sensor 50, and the bottom surface (i.e., the toner surface) of the developer container 32 in contact with the toner are arranged in this order. For example, even if toner is already present in the developer container 32, the detection described in the first to third embodiments can be performed when toner replenishment is performed in the drive-stopped state. In cases where only a very small amount of toner is present in the developer container 32 and the rotation drive of each component is started without toner replenishment, critical components may be damaged. In this case, by performing the detection described in the first to third embodiments above when toner is replenished, information indicating whether there is sufficient toner in the developer container 32 before the drive operation begins can be detected. On the other hand, if a toner surface exists upstream of the toner remaining quantity detection sensor 50 in the toner dripping direction, the detection area of ​​the toner remaining quantity measurement sensor 50 is blocked by toner before the toner replenishment operation begins, and the output value does not change due to the toner replenishment operation. Therefore, the execution of the toner replenishment operation cannot be detected. When performing the toner replenishment operation, the presence of toner in the detection area of ​​the toner remaining quantity detection sensor 50 can be detected in advance, and information regarding stopping the toner filling operation can be detected only when the presence of toner in the detection area of ​​the toner remaining quantity detection sensor 50 is detected. For example, the detection of the presence of toner by the toner remaining quantity detection sensor 50 can be performed by a light receiving availability detection unit, which detects whether light emitted from the light emitting element is received by the light receiving element.

[0171] According to this disclosure, toner can be appropriately added to the developer container while minimizing damage to components.

[0172] While this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the following claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An image forming apparatus, the image forming apparatus comprising: Image-carrying components; A rotatable developer carrier is configured to supply developer to an image carrier; The first drive unit is configured to rotatably drive the developer carrier member; A developer storage unit, wherein a developer carrier is arranged in the developer storage unit and a developer is stored therein; A rotatable stirring component is arranged in the developer storage unit and configured to stir the developer; A second drive unit is configured to rotate the stirring member; A developer detection unit is arranged in the developer storage unit and configured to detect information about the developer stored in the developer storage unit; An attachment portion, including a replenishment port communicating with a developer storage unit, the attachment portion being configured to detachably receive a replenishment container; as well as, The control unit is configured to control the first drive unit and the second drive unit. The control unit is configured to perform a replenishment operation to replenish developer to the developer storage unit. During the replenishment operation, developer is replenished from the replenishment container attached to the attachment portion into the developer storage unit through the replenishment port. The supplementary operation is performed when the developer carrier and the stirring member are stopped rotating, without rotating the developer carrier and the stirring member. The control unit is configured to control the first drive unit and the second drive unit based on information about the developer during the supplementary operation.

2. The image forming apparatus according to claim 1, wherein, The control unit is configured to control the first drive unit and the second drive unit based on information about the developer stored in the developer storage unit detected during supplementary operation.

3. The image forming apparatus according to claim 1, wherein, The first driving unit and the second driving unit share a common driving source.

4. The image forming apparatus according to claim 2, wherein, The developer carrier is configured to rotate by rotating the stirring member.

5. The image forming apparatus according to claim 1, further comprising: A movable component is configured to move to an open position and a closed position, in which the replenishment port is exposed, allowing developer to be replenished from the replenishment container to the developer storage unit; and in the closed position, the replenishment port is blocked, preventing developer from being replenished from the replenishment container to the developer storage unit. Specifically, during the period from the detection of information indicating that the movable member is in the closed position to the detection of information indicating that the movable member is in the open position, the control unit is configured to control the developer detection unit to detect information about the developer.

6. The image forming apparatus according to claim 5, wherein, When information indicating that the movable component is in the closed position is detected, the control unit is configured to control the developer detection unit to terminate the detection of information about the developer.

7. The image forming apparatus according to claim 5, wherein, When information indicating that the movable member is in the open position is detected, the control unit is configured to control the developer detection unit to begin detecting information about the developer.

8. The image forming apparatus according to any one of claims 1 to 7, wherein, The control unit controls the first drive unit and the second drive unit based on information about the developer detected when information indicating that the movable member is in the closed position is detected.

9. The image forming apparatus according to claim 1, wherein, The information about the developer is a first value, which is information about the developer dosage stored in the developer storage unit.

10. The image forming apparatus according to claim 9, further comprising: A storage unit configured to store a first threshold for the first value. Wherein, if the first value exceeds the first threshold, the control unit is configured to perform a second operation for rotating the stirring member after the supplementary operation that is the first operation.

11. The image forming apparatus according to claim 10, further comprising: The display unit is configured to display information about the developer in the developer storage unit. Wherein, if the first value does not exceed the first threshold, the control unit is configured to control the display unit to display information indicating that the developer has not yet been replenished to the developer storage unit or information prompting the replenishment of the developer from the replenishment container to the developer storage unit.

12. The image forming apparatus according to claim 10, in, The storage unit is configured to store a second threshold that is different from the first threshold, and In the second operation, if the first value exceeds the second threshold, the control unit is configured to perform a preparation operation to be performed before the image forming operation for forming an image on the recording material after the second operation.

13. The image forming apparatus according to claim 12, further comprising: The display unit is configured to display information about the developer in the developer storage unit. Wherein, if the first value does not exceed the second threshold, the control unit is configured to control the display unit to display information indicating that the developer has not been replenished to the developer storage unit or information prompting the replenishment of developer from the replenishment container to the developer storage unit.

14. The image forming apparatus according to claim 9, in, The developer detection unit includes: Light incident section, light emitted by the image forming apparatus enters through the light incident section, and A light emitting section is configured to allow light to pass through a light receiving unit disposed in an image forming apparatus, and The developer detection unit is configured to detect an output voltage, which is a first value corresponding to the light received by the light receiving unit.

Images